Method for Preparing Norbornene Monomer Composition, Norbornene Polymer Prepared Therefrom, Optical Film Comprising the Norbornene Polymer, and Method for Preparing the Norbornene Polymer

ABSTRACT

Disclosed is a method for producing a norbornene monomer composition, a norbornene polymer produced using the norbornene monomer composition, an optical film including the norbornene polymer, and a method for producing the norbornene polymer. The method includes reacting a reaction solution that contains cyclopentadiene, dicyclopentadiene, or a mixture of cyclopentadiene and dicyclopentadiene, an acetate compound, and a solvent so that a content of an exo isomer is 50 mol % or more. Variables such as a reaction temperature, a reaction time, a molar ratio between reactants, and addition of a solvent are controlled so that the exo isomer is contained in content of 50 mol % or more. Accordingly, it is possible to industrially produce an acetate norbornene addition polymer by using the acetate norbornene monomer composition containing the exo isomer in content of 50 mol % or more.

TECHNICAL FIELD

The present invention relates to a method for producing a norbornenemonomer composition, a norbornene polymer produced using the norbornenemonomer composition, an optical film including the norbornene polymer,and a method for producing the norbornene polymer. More particularly,the present invention relates to a method for producing a polarnorbornene monomer composition that contains an exo isomer in content of50 mol % or more, a norbornene polymer produced using the method, anoptical film including the norbornene polymer, and a method forproducing the norbornene polymer.

BACKGROUND ART

A thermoplastic norbornene addition polymer that includes a polarfunctional group is transparent and has low dielectric constant andhygroscopic property. Furthermore, the norbornene addition polymer isexcellent in terms of thermal stability, mechanical strength, andadhesion strength, and generates no byproducts when being attached tometal or other polymers. The norbornene addition polymer may be used ina polarizer protection film, an optical film such as a retardation film,a plastic substrate material, a transparent polymer such as POF, a PCB,or an insulating electronic material such as an insulating substance.

However, when an addition polymer is produced by using a norbornenemonomer having a polar functional group, in the case where the monomeris the endo isomer, a polymerization speed is lower, a polymer has alower molecular weight, and a polymerization yield is lower as comparedto the case where the monomer is the exo isomer.

For example, according to Risse et al., if a norbornene derivativehaving a polar functional group such as an ester group is produced byusing a palladium catalyst (Pd(CH₃CN)₄)[BF₄]₂), in the case where theratio of endo isomer is higher among exo and endo isomers of theester-norbornene monomer (exo/endo=20/80 and yield 23 to 30%), thepolymerization yield and the molecular weight are lower as compared tothe case where polymerization is performed by using only the exo isomer(yield 70% or more) ((a) Risse et al.; Makromol. Chem., 1992, Vol. 193,2915-2927; (b) Risse et al.; Macromolecules, 1996, Vol. 29, 2755-2763).

The reason why the polymerization yield and the molecular weight arelower is that unshared electron pairs of the polar functional group ofthe endo type substituent are strongly bonded to vacant sites of a metalcatalyst to prevent the norbornene monomers from approaching the metal,thereby slowing down the polymerization. For example, in the case wherenorbornene has an endo type ester group, a complex is stabilized and theunshared electron pairs of the oxygen atom partially provide electronsto the metal atom due to a chelate effect where an oxygen atom of acarbonyl group that is contained in the ester group is bonded to a metalcatalyst. Thus, a catalytic activity of the metal atom is reduced ((a)Sen et al.; Organometallics 2004, 23, 1680-1683; (b) Sen et al.;Organometallics 2001, 20, 2802-2812; (c) Sen et al.; Acc. Chem. Res.1993, 26, 303-310; (d) Risse et al. Macromolecules 1996, 29,2755-2763.).

Accordingly, in the addition polymerization of the norbornene monomerhaving the polar functional group, only the exo isomer may be used orthe monomer that contains the exo isomer in a large amount (an excessiveamount of exo) may be used to significantly increase the molecularweight while the yield is not reduced during the production of thepolymer. In addition, in the case where a film is produced by using theabove-mentioned polymer, viscosity of a film production solution isincreased, the modulus of the film is improved, and surface hardness isimproved. Hence, it is possible to produce a film having excellentmechanical properties. Therefore, it is very important to ensure areaction condition capable of controlling a ratio of norbornene isomers(endo and exo isomers).

However, a known method for producing a norbornene monomer having apolar functional group by using a catalyst such as a Lewis acid isproblematic in that an endo isomer is generated in a large amount (Chem.Rev. 1961, 61, 537-562).

For example, in the case of a 5-norbornene-2-methyl acetate monomer, aproduction method by using norbornene methanol(bicyclo[2.2.1]hept-5-enyl-2-methanol) is known in the art. However, aplurality of stages are performed in the method, and the resultingcompound contains the large amount of endo isomer so that a ratio ofexo/endo isomers is 20/80 ((a) Castner, K. F.; Calderon, N. J. Mol.Catal. 1982, 15, 47.; (b) Risse et al.; Makromol. Chem. 1992, 193, 2915.(c) Roberts et al.;. J. Am. Chem. Soc. 1950, 72, 3116. (d) Ver Nooy etal. J. Am. Chem. Soc. 1955, 77, 3586. (e) Arjona et al. J. Org. Chem.1991, 56, 6227. (f) Nelson et al. Synthesis 1975, 105. (g) Magoon et al.J. Organomet. Chem. 1973, 55, 409.).

That is, it is difficult to achieve synthesis of a pure exo isomer of5-norbornene-2-methyl acetate by using a simple process, and a pluralityof stages must be performed in known processes. Accordingly, there is aneed to provide a method of industrially producing a norbornene monomercontaining an excessive amount of exo isomer by using a simple process.

It is known that a sterical chemical of a product depends on polar ornonpolar properties of a solvent in a Diels-Alder reaction (Otto et al.;J. Am. Chem. Soc. 1996, 118, 7702). However, a ratio of an exo isomerproduct to an endo isomer product is not more than 33%.

Therefore, there remains a need to provide a method of industriallyproducing a norbornene monomer that is used to produce an additionpolymer of the norbornene monomer having a polar functional group, hasthe polar functional group, and contains an excessive amount of exoisomer by using a simple process so that the yield of polymer isimproved and the molecular weight is increased.

DISCLOSURE Technical Problem

An object of the present invention is to provide a method for producingan acetate norbornene monomer composition containing an exo isomer incontent of 50 mol % or more. The method includes controlling variablessuch as a reaction temperature, a reaction time, a molar ratio betweenreactants, and addition of a solvent while a catalyst is not added.

Another object of the present invention is to provide a norbornenepolymer produced using an acetate norbornene monomer compositioncontaining an exo isomer in content of 50 mol % or more.

Still another object of the present invention is to provide an opticalfilm including the norbornene polymer.

Yet another object of the present invention is to provide a method forproducing the norbornene polymer.

Technical Solution

The present invention provides a method for producing a norbornenemonomer composition. The method includes reacting a reaction solutionthat contains cyclopentadiene, dicyclopentadiene, or a mixture ofcyclopentadiene and dicyclopentadiene, a compound represented by Formula1, and a solvent at a reaction temperature of 230 to 330° C. for areaction time of 0.1 to 24 hours so that a content of an exo isomer is50 mol % or more.

CH₂═CH—(CH₂)_(n)—OC(O)R  <Formula 1>

wherein n is an integer of 0 to 10, and R is an alkyl group having 1 to20 carbon atoms.

Advantageous Effects

According to the present invention, in order to produce an acetatenorbornene monomer composition containing an exo isomer in content of 50mol % or more, variables such as a reaction temperature, a reactiontime, a molar ratio between reactants, and addition of a solvent arecontrolled. Thus, it is possible to industrially produce the acetatenorbornene monomer composition, a norbornene polymer produced using thecomposition, and an optical film including the polymer using an easyprocess.

DESCRIPTION OF DRAWINGS

FIG. 1 is an NMR spectrum of a pure exo isomer of 5-norbornene-2-methylacetate;

FIG. 2 is an NMR spectrum of a pure endo isomer of 5-norbornene-2-methylacetate; and

FIG. 3 is an NMR spectrum of 5-norbornene-2-methyl acetate produced inExample 9.

BEST MODE

The present invention provides a method for producing a norbornenemonomer composition. The method includes reacting a reaction solutionthat contains cyclopentadiene, dicyclopentadiene, or a mixture ofcyclopentadiene and dicyclopentadiene; a compound represented by Formula1; and a solvent; at a reaction temperature of 230 to 330° C. for areaction time of 0.1 to 24 hours so that a content of an exo isomer is50 mol % or more.

CH₂═CH—(CH₂)_(n)—OC(O)R  <Formula 1>

wherein n is an integer of 0 to 10, and R is an alkyl group having 1 to20 carbon atoms.

Furthermore, the present invention provides a norbornene polymerincluding a repeating unit that is represented by Formula 2 and containsan exo isomer in a content of 50 mol % or more.

wherein m is an integer of 0 to 4, n is an integer of 0 to 10, and R isan alkyl group having 1 to 20 carbon atoms.

Furthermore, the present invention provides an optical film includingthe norbornene polymer.

Furthermore, the present invention provides a method for producing anorbornene polymer that is represented by Formula 5. The method includesbringing a reactant that contains a norbornene monomer compositionhaving an exo isomer in a content of 50 mol % or more into contact witha catalyst of a transition metal of Group 10.

wherein m is an integer of 0 to 4, n is an integer of 0 to 10, and R isan alkyl group having 1 to 20 carbon atoms.

Hereinafter, the present invention will be described in more detail.

Unlike a known method where a polar norbornene monomer compositioncontaining an exo isomer in content of 50 mol % or more is producedthrough a complicated process, the present invention provides a methodfor producing an acetate norbornene monomer composition containing anexo isomer in content of 50 mol % or more, which includes controllingvariables such as a reaction temperature, a reaction time, a molar ratiobetween reactants, and addition of a solvent while a catalyst is notadded, a norbornene polymer produced using the norbornene monomercomposition, an optical film including the norbornene polymer, and amethod for producing the norbornene polymer.

In order to confirm a difference in physical properties of an endoisomer and an exo isomer used in the present invention, the pure endoisomer and the pure exo isomer were produced by using a known method toensure different polymerization activities according to the type ofisomer. In addition, a difference in molecular weight of the polymerthat is produced by using the isomers was confirmed.

It is difficult to obtain the pure exo isomer or the endo isomer of5-norbornene-2-methyl acetate by a simple synthesis method, and aplurality of steps must be performed in the known process.

<Pre-Test to Confirm a Difference in Physical Properties of the EndoIsomer and the Exo Isomer>

Each of the pure exo isomers and the pure endo isomers of5-norbornene-2-methyl acetate were polymerized by using a{[Allyl(PdCl)]₂+AgSbF₆} catalyst that was disclosed in the paper setforth by Risse et al., thereby the fact that the molecular weights andthe polymerization activities of the addition polymers were differentfrom each other according to the type of isomer was confirmed.

FIG. 1 is an NMR spectrum of a pure exo isomer of 5-norbornene-2-methylacetate, and FIG. 2 is an NMR spectrum of a pure endo isomer of5-norbornene-2-methyl acetate.

In the present invention, in the case of the pure exo isomer monomer,the viscosity was significantly increased after 7 min, to render thepolymerization reaction finished. However, in the case of the pure endoisomer monomer, the viscosity of the reaction solution was notsignificantly increased even though the reaction was performed for 4hours.

The yield of the addition polymer of the pure exo isomer monomers in thecase where the reaction was finished after 15 min was 95.5% and theyield of the addition polymer of the pure endo isomer monomers in thecase where the reaction was finished after 4 hours was 64.0%. Thus,there was a significant difference in yield.

In addition, the number average molecular weight (Mn) of the additionpolymer of the pure endo isomer monomers was about 24.1 K/mol, but thenumber average molecular weight (Mn) of the addition polymer of the pureexo isomer monomers was about 219.4 K/mol. Hence, it could be seen thatthe number average molecular weight of the addition polymer of the pureexo isomer monomers was 9 times as high as that of the addition polymerof the pure endo isomer monomers.

Furthermore, an optical isotropic film was produced by using theabove-mentioned polymer to measure physical properties. Thereby, itcould be seen that the optical and mechanical properties of the filmthat is produced by using the addition polymer varied according to thetype of isomer.

Therefore, it can be seen that the physical properties significantlydepend on the type of isomer and it is very important to provide anexcessive amount of exo isomer in views of mass production.

The present invention provides a method for producing a norbornenemonomer composition. The method includes reacting a reaction solutionthat contains cyclopentadiene, dicyclopentadiene, or a mixture ofcyclopentadiene and dicyclopentadiene; a compound represented by Formula1; and a solvent; at a reaction temperature of 230 to 330° C. for areaction time of 0.1 to 24 hours so that a content of an exo isomer is50 mol % or more.

CH₂═CH—(CH₂)_(n)—OC(O)R  <Formula 1>

wherein n is an integer of 0 to 10, and R is an alkyl group having 1 to20 carbon atoms.

Based on the fact that a Diels-Alder reaction is a reversible reaction,a reaction temperature was set to be high and a solvent was used inorder to produce a large amount of thermodynamically stable exo isomerswhen cyclopentadiene and the compound represented by Formula 1 arereacted with each other, thereby the present invention was accomplished.

The reason why the exo isomer is contained in content of 50 mol % ormore will be described below. This description are set forth toillustrate, but are not to be construed to limit the present invention.

From comparison of reaction energies of the endo isomer and the exoisomer having an acetate functional group in the Diels-Alder reaction,the following fact can be known.

In the case where 5-norbornene-2-methyl acetate is produced through theDiels-Alder reaction of cyclopentadiene (Cp) and allyl acetate, theenergy of the transition state and the energy of the reaction productare as shown in Reaction scheme 1.

In views of the energy of the transition state of the productionreaction, the endo isomer is more stable than the exo isomer by about1.2 kcal/mol. However, in views of the energy of the reaction product,the exo isomer is more stable than the endo isomer by about 2.1kcal/mol. This can be confirmed by using the DFT (Density functionaltheory) calculation. The detailed description of the calculation isgiven in Calculation example 1.

Accordingly, in views of reaction kinetics, since the transition stateof the endo isomer is stable, the endo isomer is competitive in terms ofenergy in the Diels-Alder reaction. Thus, the endo isomer can be easilyproduced. In views of thermodynamics, since the reaction product of theexo isomer is stable, the exo isomer is competitive in terms of energyin the Diels-Alder reaction. Hence, in the case where the reaction timeand the reaction temperature are controlled to form a state that isuseful to produce thermodynamically stable isomers, monomers thatconsist mostly of the exo isomers can be synthesized.

In the Diels-Alder reaction where the polar functional group is used, itis more difficult to react an acetyl group and cyclopentadiene to formthe exo isomer in comparison with an ester group. The reason can be seenby comparison of reaction energies of the endo isomer and the exoisomer.

For example, in the case where methyl ester norbornene is produced byusing the Diels-Alder reaction of cyclopentadiene and methyl acrylate,the energy of the transition state and the energy of the reactionproduct in the reaction are as shown in Reaction scheme 2.

That is, in the production reaction of the ester norbornene, adifference in energy of the transition state of the exo isomer and theendo isomer is about 0.2 kcal/mol. However, in the production reactionof the acetate norbornene (5-norbornene-2-methyl acetate) (<Reactionscheme 1>), a difference in energy of the transition state of the exoisomer and the endo isomer is about 1.2 kcal/mol which is higher thanthat of the case of the production reaction of the ester norbornene.

That is, in the acetyl group, stability of the transition state of theendo isomer is still higher than that of the exo isomer in comparisonwith that in the ester group. However, a difference in energy of the exoisomer and the endo isomer of the reaction product is about 2.2 kcal/molin the case of the ester group and about 2.1 kcal/mol in the case of theacetyl group. Thus, the exo isomer is insignificantly different from theendo isomer in terms of the difference in energy of the reactionproduct.

In the case of dicyclopentadiene, a ring-opening reaction occurs in therange of the reaction temperature to convert dicyclopentadiene intocyclopentadiene, and the subsequent reaction may be progresses accordingto the same mechanism as cyclopentadiene.

A ratio of the exo/endo isomers that are generated during a Diels-Alderreaction is known to be changed according to the polarity of a solvent(Otto et al.; J. Am. Chem. Soc. 1996, 118, 7702).

However, the cited document does not suggest the condition that contentof the exo isomer is 50 mol % or more. Accordingly, it can be seen thatit is difficult to increase the relative amount of the exo isomer bychanging only the polarity of the solvent.

In the method for producing the monomer composition according to thepresent invention, examples of the solvent include, but are not limitedto cyclohexane, toluene, acetone, methyl ethyl ketone (MEK), ethylacetate, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), dimethylformamide (DMF), and a mixture thereof.

In addition, the present invention provides a method for producing anorbornene monomer composition so that content of the exo isomer is 50mol % or more by using a change in temperature as well as polarity ofthe solvent.

In the present invention, in order to produce the norbornene monomercontaining the excessive amount of exo isomer having the polarfunctional group, the reaction temperature is preferable 230 to 330° C.and more preferably 270 to 330° C. In the case where the reactiontemperature is lower than 230° C., it is impossible to produce thenorbornene monomer containing the excessive amount of exo isomer havingthe polar functional group. In the case where the reaction temperatureis higher than 330° C., there is a problem in that the production yieldof monomer is reduced due to increased byproducts or decomposition ofproducts.

Additionally, in the present invention, since the reaction temperatureis maintained at about 23° C. or more, instead of cyclopentadiene thatis one of raw materials used to produce the norbornene monomer, morestable dicyclopentadiene can be used.

Since cyclopentadiene is unstable at normal temperature and thus easilyconverted into dicyclopentadiene, it is difficult to maintain purecyclopentadiene. However, dicyclopentadiene is decomposed at 180° C. ormore to participate in the reaction while dicyclopentadiene is dividedinto two cyclopentadiene molecules. Thus, in the present invention, bothcyclopentadiene and dicyclopentadiene are capable of being used as rawmaterials of the reaction. Accordingly, since it is unnecessary topurify cyclopentadiene from dicyclopentadiene, there is an advantage inthat the production process is simple.

Furthermore, although the reaction is not affected by the pressure, anincrease in pressure may occur due to vaporization of the reactants athigh temperatures during the reaction and the reaction may be performedin the range of 1 to 30 atm.

Additionally, the reaction time may be in the range of 5 min to 24hours, preferably 5 min to 16 hours, and more preferably 5 min to 5hours. This is because the reaction time affects the degree of reactionand a change in selectivity. That is, in the reaction in the range of 5min or less, even though the reaction temperature is increased to 330°C., it is difficult to obtain the compound containing the excessiveamount of exo isomer. If the reaction time is 24 hours or more, it ispossible to obtain the compound containing the excessive amount of exoisomer but many side reactions occur, which reduces the yield.

In respects to the correlation of the reaction temperature and thereaction time, it is preferable to perform the reaction so that thereaction quotient represented by the following Equation 1 be 25,200 to350,000.

Reaction quotient=reaction temperature (° C.)₂×log(reaction time(min))  <Equation 1>

That is, in the case where the reaction is performed at the temperaturein the range of 230 to 330° C. which satisfies the above-mentionedreaction temperature condition, it is preferable that the reaction beperformed so that the above-mentioned reaction index is satisfied inorder to increase the content of exo isomer and the production yield ofthe monomer.

In the production method according to the present invention, the molarratio of the compound represented by Formula 1 to cyclopentadiene,dicyclopentadiene, or a mixture thereof among the above-mentionedreactants may be in the range of 1:0.1 to 1:10, preferably 1:0.5 to1:10, and more preferably 1:0.5 to 1:5. This is because the molar ratiodepends on the degree of reaction and the selectivity.

In the case where the molar ratio of the compound represented by Formula1 is 1:1 or more, the acetate norbornene monomer composition where m is0 in Formula 5 is generated as a main product. In the case where themolar ratio is less than 1:1, the acetate norbornene monomer compositionwhere m is 1 to 4 in Formula 5 is generated as a main product.

wherein m is an integer of 0 to 4, n is an integer of 0 to 10, and R isan alkyl group having 1 to 20 carbon atoms.

Additionally, in the production method according to the presentinvention, in order to prevent the reactants and the products from beingpolymerized or decomposed during the reaction, it is preferable to add apolymerization inhibitor during the reaction.

Examples of the polymerization inhibitor include, but are not limited toone or more compounds selected from the group consisting of aniline,cyclohexane, phenol, 4-ethoxyphenol, nitrobenzene, hydroquinone,benzoquinone, copper dichloride, and2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl, and Irganox.

Specific examples of Irganox may include Irganox 1010, Irganox 1035,Irgarnox 1076, Irganox 1081, Irganox 1098, Irganox 1135, Irganox 1330,Irganox 1520, Irganox 1726, and Irganox 245.

Additionally, in the production method of the monomer compositionaccording to the present invention, it is preferable that a weight ratioof the polymerization inhibitor to the total weight of the reactant suchas cyclopentadiene (Cp), dicyclopentadiene (DCPD), or a mixture thereof,and the compound represented by Formula 1 be in the range of 1:0.0001 to1:10. In the case where the weight ratio is less than 1:0.0001, it isimpossible to efficiently prevent self-polymerization of the reactant(Cp or DCPD). Even though the weight ratio is 1:10, the function of thepolymerization inhibitor is sufficiently realized.

That is, even though the amount of polymerization inhibitor isincreased, the increased amount does not affect the yield. In the casewhere the large amount of inhibitor is used, there is a problem in thatit is necessary to remove the polymerization inhibitor after thesynthesis is finished. However, in the present invention, addition ofthe polymerization inhibitor is not essential.

Meanwhile, in the case where n is in the range of 0 in Formula 1, theabove-mentioned norbornene monomer composition may contain 50 to 100 mol% of exo isomer. In the case where n is in the range of 1 to 10, thenorbornene monomer composition may contain 50 to 90 mol % of exo isomer,but the content is not limited thereto.

The present invention provides a norbornene polymer including arepeating unit that is represented by Formula 2 and contains an exoisomer in a content of 50 mol % or more.

wherein m is an integer of 0 to 4, n is an integer of 0 to 10, and R isan alkyl group having 1 to 20 carbon atoms.

In connection with this, in the case of norbornene polymer, n is 0 andthe content of the exo isomer in the repeating unit is 50 to 100 mol %.Alternatively, in the norbornene polymer, n is in the range of 1 to 10and the content of the exo isomer in the repeating unit is 50 to 90 mol%.

The degree of polymerization of the norbornene polymer is in the rangeof preferably 10 to 20,000 and more preferably 10 to 10,000.

Hereinafter, specific embodiments of the norbornene polymer according tothe present invention will be described. The embodiments are set forthto illustrate, but are not to be construed to limit the presentinvention.

According to a first embodiment of the present invention, theabove-mentioned norbornene polymer may be a homopolymer containing arepeating unit selected from the compounds represented by Formula 2.

According to a second embodiment of the present invention, theabove-mentioned norbornene polymer may be a copolymer containing atleast two repeating units selected from the compounds represented byFormula 2.

According to a third embodiment of the present invention, theabove-mentioned norbornene polymer may be a copolymer further containinga polar norbornene repeating unit of Formula 3, if necessary.

wherein m is an integer of 0 to 4,

at least one of R_(1a), R_(2a), R_(3a), and R_(4a) is a polar functionalgroup containing at least one atom selected from the group consisting ofoxygen, nitrogen, phosphorus, sulfur, silicon, and boron, and

R_(1a), R_(2a), R_(3a), and R_(4a) that are not the polar functionalgroup are each independently hydrogen; halogen; linear or branchedalkyl, alkenyl, or vinyl having 1 to 20 carbon atoms; cycloalkyl that issubstituted or unsubstituted with hydrocarbon and has 5 to 12 carbonatoms; aryl that is substituted or unsubstituted with hydrocarbon andhas 6 to 40 carbon atoms; aralkyl that is substituted or unsubstitutedwith hydrocarbon and has 7 to 15 carbon atoms; alkynyl that has 3 to 20carbon atoms; linear or branched haloalkyl, haloalkenyl, or halovinylthat has 1 to 20 carbon atoms; halocycloalkyl that is substituted orunsubstituted with hydrocarbon and has 5 to 12 carbon atoms; haloarylthat is substituted or unsubstituted with hydrocarbon and has 6 to 40carbon atoms; haloaralkyl that is substituted or unsubstituted withhydrocarbon and has 7 to 15 carbon atoms; haloalkynyl that has 3 to 20carbon atoms; an alkylidene group that is formed by bonding of R_(1a)and R_(2a) or R_(3a) and R_(4a) and has 1 to 10 carbon atoms; asaturated or unsaturated cyclic group that is formed by bonding ofR_(1a) or R_(2a) to either of R₃₂ and R_(4a) and has 4 to 12 carbonatoms; or an aromatic cyclic compound that has 6 to 24 carbon atoms.

According to a fourth embodiment of the present invention, theabove-mentioned norbornene polymer may be a copolymer further containinga nonpolar norbornene repeating unit of Formula 4, if necessary.

wherein m is an integer of 0 to 4, and

R_(1b), R_(2b), R_(3b), and R_(4b) are each independently hydrogen;halogen; linear or branched alkyl, alkenyl, or vinyl having 1 to 20carbon atoms; cycloalkyl that is substituted or unsubstituted withhydrocarbon and has 5 to 12 carbon atoms; aryl that is substituted orunsubstituted with hydrocarbon and has 6 to 40 carbon atoms; aralkylthat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; alkynyl that has 3 to 20 carbon atoms; linear or branchedhaloalkyl, haloalkenyl, or halovinyl that has 1 to 20 carbon atoms;halocycloalkyl that is substituted or unsubstituted with hydrocarbon andhas 5 to 12 carbon atoms; haloaryl that is substituted or unsubstitutedwith hydrocarbon and has 6 to 40 carbon atoms; haloaralkyl that issubstituted or unsubstituted with hydrocarbon and has 7 to 15 carbonatoms; haloalkynyl that has 3 to 20 carbon atoms; an alkylidene groupthat is formed by bonding of R_(1b) and R_(2b) or R_(3b) and R_(4b) andhas 1 to 10 carbon atoms; a saturated or unsaturated cyclic group thatis formed by bonding of R_(1b) or R_(2b) to either of R_(3b) and F_(4b)and has 4 to 12 carbon atoms; or an aromatic cyclic compound that has 6to 24 carbon atoms.

According to a fifth embodiment of the present invention, theabove-mentioned norbornene polymer may be a copolymer further containinga polar norbornene repeating unit of Formula 3 and a nonpolar norbornenerepeating unit of Formula 4, if necessary.

In the copolymer according to the third embodiment and the fifthembodiment, examples of the polar functional group that is contained inthe polar norbornene repeating unit of Formula 3 include —C(O)OR₆,—R₅C(O)OR₆, —OR₆, —R₅OR₆, —OC(O)OR₆, —R₅OC(O)OR₆, —C(O)R₆, —R₅C(O)R₆,—OC(O)₆, —R₅OC(O)R₆, —(R₅₀)_(p)—OR₆, —(OR₅)_(p)—OR₆, —C(O)—O—C(O)R₆,—R₅C(O)—O—C(O)R₆, —SR₆, —R₅SR₆, —SSR₆, —R₅SSR₆, —S(═O)R₆, —R₅S(═O)R₆,—R₅C(═S)R₆, —R₅C(═S)SR₆, —R₅SO₃R₅, —SO₃R₆, —R₅N═C═S, —N═C═S, —NCO,R₅—NCO, —CN, —R₅CN, —NNC(═S)R₆, —R₅NNC(═S)R₆, —NO₂, —R₅NO₂,

wherein each R₅ is independently linear or branched alkylene,haloalkylene, alkenylene, haloalkenylene, vinylene, or halovinylene thathas 1 to 20 carbon atoms; cycloalkylene or halocycloalkylene that issubstituted or unsubstituted with hydrocarbon and has 4 to 12 carbonatoms; arylene or haloarylene that is substituted or unsubstituted withhydrocarbon and has 6 to 40 carbon atoms; aralkylene or haloaralkylenethat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; or alkynylene or haloalkynylene that has 3 to 20 carbonatoms,

each R₆, R₇, and R₉ are independently hydrogen; halogen; linear orbranched alkyl, haloalkyl, alkenyl, haloalkenyl, vinyl, halovinyl,alkoxy, haloalkoxy, carbonyloxy, or halocarbonyloxy that has 1 to 20carbon atoms; cycloalkyl or halocycloalkyl that is substituted orunsubstituted with hydrocarbon and has 4 to 12 carbon atoms; aryl,haloaryl, aryloxy, or haloaryloxy that is substituted or unsubstitutedwith hydrocarbon and has 6 to 40 carbon atoms; aralkyl or haloaralkylthat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; or alkynyl or haloalkynyl that has 3 to 20 carbon atoms,and

each p is independently an integer of 1 to 10.

In the copolymer according to the third embodiment, the molar ratio ofthe acetate norbornene repeating unit of Formula 2 and the polarnorbornene repeating unit of Formula 3 depends on the required physicalproperties of the polymer, and a polymerization activity is improved asthe content of the repeating unit of Formula 2 is increased.Accordingly, the molar ratio of the repeating units of Formulae 2 and 3is in the range of preferably 1:700 to 700:1 and more preferably 1:100to 100:1.

In the copolymer according to the fourth embodiment, the molar ratio ofthe acetate norbornene repeating unit of Formula 2 and the nonpolarnorbornene repeating unit of Formula 4 depends on the required physicalproperties of the polymer. Because of the same reason, the molar ratioof the repeating units of Formulae 2 and 4 is preferably 1:700 to 700:1and more preferably 1:100 to 100:1.

Furthermore, in the copolymer according to the fifth embodiment, themolar ratio of the acetate norbornene repeating unit of Formula 2 andthe repeating units of Formulae 3 and 4 depends on the required physicalproperties of the polymer. Because of the same reason, it is preferablethat the molar ratio of the repeating unit of Formula 2 and the sum ofthe repeating units of Formulae 3 and 4 be 1:1,400 to 1, 400:1 and themolar ratio of the polar repeating unit of Formula 3 and the nonpolarrepeating unit of Formula 4 be 1:700 to 700:1. It is more preferablethat the molar ratio of the repeating unit of Formula 2 and the sum ofthe repeating units of Formulae 3 and 4 be 1:500 to 500:1 and the molarratio of the polar repeating unit of Formula 3 and the nonpolarrepeating unit of Formula 4 be 1:100 to 100:1.

The present invention provides an optical film that includes thenorbornene polymer.

Preferable examples of the optical film include, but are not limited toa polarizer protection film for LCDs or a plastic substrate that is asubstitute for a glass substrate, and the optical film may be used asvarious types of optical materials within the scope of the presentinvention.

Specifically, it is preferable that the optical film have the opticalanisotropic property so that the retardation value (R_(th)) representedby Equation 1 is 70 to 1000 nm.

R _(th)=Δ(n _(y) −n _(z))×d  <Equation 1>

wherein n_(y) is an in-plane refractive index of a fast axis that ismeasured at a wavelength of 550 mm, n_(z) is a thickness refractiveindex that is measured at a wavelength of 550 nm, and d is a thicknessof a film.

In addition, preferably, the optical film is a negative C-plate typeoptical compensation film for liquid crystal displays (LCDs) satisfyinga refractive index correlation where n_(x)≈n_(y)>n_(z) (n_(x) is anin-plane refractive index of a slow axis, n_(y) is the refractive indexof a fast axis, and n_(z) is a thickness refractive index).

Furthermore, the present invention provides a method for producing anorbornene polymer that is represented by Formula 5. The method includesbringing a reactant that contains a norbornene monomer compositionhaving an exo isomer in a content of 50 mol % or more into contact witha catalyst of a transition metal of Group 10.

wherein m is an integer of 0 to 4, n is an integer of 0 to 10, and R isan alkyl group having 1 to 20 carbon atoms.

Examples of the catalyst of the transition metal of Group 10 may includea known catalyst for cyclic olefin polymerization used in the art suchas a Pd metal catalyst. Like a known polymerization method, since theabove-mentioned polymer system is produced by mixing monomers to bepolymerized, a catalyst, and a solvent and polymerizing the resultingreaction mixture, it is not limited thereto.

In the method for producing the norbornene polymer, the monomercomposition contains only any one monomer selected from the compounds ofFormula 5, but is not limited thereto. The monomer composition maycontain at least two monomers selected from the compounds of Formula 5to remove the copolymer according to the second embodiment, or maycontain the polar norbornene monomer of Formula 6, the nonpolarnorbornene polymer of Formula 7, or the polar norbornene monomer and thenonpolar norbornene polymer to produce the copolymers of the third tofifth embodiments if necessary.

wherein each m is independently an integer of 0 to 4,

at least one of R_(1a), R_(2a), R_(3a), and R_(4a) is a polar functionalgroup containing at least one atoms selected from the group consistingof oxygen, nitrogen, phosphorus, sulfur, silicon, and boron, and

R_(1a), R_(2a), R_(3a), and R_(4a) that are not the polar functionalgroup are each independently hydrogen; halogen; linear or branchedalkyl, alkenyl, or vinyl having 1 to 20 carbon atoms; cycloalkyl that issubstituted or unsubstituted with hydrocarbon and has 5 to 12 carbonatoms; aryl that is substituted or unsubstituted with hydrocarbon andhas 6 to 40 carbon atoms; aralkyl that is substituted or unsubstitutedwith hydrocarbon and has 7 to 15 carbon atoms; alkynyl that has 3 to 20carbon atoms; linear or branched haloalkyl, haloalkenyl, or halovinylthat has 1 to 20 carbon atoms; halocycloalkyl that is substituted orunsubstituted with hydrocarbon and has 5 to 12 carbon atoms; haloarylthat is substituted or unsubstituted with hydrocarbon and has 6 to 40carbon atoms; haloaralkyl that is substituted or unsubstituted withhydrocarbon and has 7 to 15 carbon atoms; haloalkynyl that has 3 to 20carbon atoms; an alkylidene group that is formed by bonding of R_(1a)and R_(2a) or R_(3a) and R_(4a) and has 1 to 10 carbon atoms; asaturated or unsaturated cyclic group that is formed by bonding ofR_(1a) or R_(2a) to either of R_(3a) and R_(4a) and has 4 to 12 carbonatoms; or an aromatic cyclic compound that has 6 to 24 carbon atoms, and

each R_(1b), R_(2b), R_(3b), and R_(4b) are independently hydrogen;halogen; linear or branched alkyl, alkenyl, or vinyl having 1 to 20carbon atoms; cycloalkyl that is substituted or unsubstituted withhydrocarbon and has 5 to 12 carbon atoms; aryl that is substituted orunsubstituted with hydrocarbon and has 6 to 40 carbon atoms; aralkylthat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; alkynyl that has 3 to 20 carbon atoms; linear or branchedhaloalkyl, haloalkenyl, or halovinyl that has 1 to 20 carbon atoms;halocycloalkyl that is substituted or unsubstituted with hydrocarbon andhas 5 to 12 carbon atoms; haloaryl that is substituted or unsubstitutedwith hydrocarbon and has 6 to 40 carbon atoms; haloaralkyl that issubstituted or unsubstituted with hydrocarbon and has 7 to 15 carbonatoms; haloalkynyl that has 3 to 20 carbon atoms; an alkylidene groupthat is formed by bonding of R_(1b) and R_(2b) or R_(3b) and R_(4b) andhas 1 to 10 carbon atoms; a saturated or unsaturated cyclic group thatis formed by bonding of R_(1b) or R_(2b) to either of R_(3b) and R_(4b)and has 4 to 12 carbon atoms; or an aromatic cyclic compound that has 6to 24 carbon atoms.

However, during the production of the copolymer according to the thirdto the fifth embodiments, the ratio of the monomers to be used may becontrolled to be the same as the above-mentioned molar ratio of therepeating units of the copolymers.

Mode for Invention

A better understanding of the present invention may be obtained in lightof the following Examples which are set forth to illustrate, but are notto be construed to limit the present invention.

EXAMPLE

All operations where compounds that are sensitive to air or water weretreated were performed by using a standard Schlenk technique or a drybox technique.

The nuclear magnetic resonance (NMR) spectrum was obtained by using aBruker 600 spectrometer and a Bruker 300 spectrometer. 1H NMR wasmeasured at 600 MHz and 300 MHz and ¹³C NMR was measured at 150 MHz and75 MHz.

In order to precisely distinguish NMR signals, various types oftwo-dimensional experiments such as COSY and HMBC were performed.

The molecular weight and the molecular weight distribution of thepolymer were measured by using GPC (gel permeation chromatography), anda polystyrene sample was used as a standard. Gas chromatography (GC)equipment that was provided with a flame ionization detector (FID) andan AT 1000 column was used.

Toluene was purified through distillation using potassium/benzophenone,and CH₂Cl₂ was distilled by using CaH₂ to be purified.

Calculation Example DTF (Density Functional Theory) Calculation

In order to calculate the activation energy and the reaction energy ofthe exo and endo 5-norbornene-2-methyl acetate isomers, a BPW91 function(Perdew, J. P.; Wang, Y. Phys. Rev., B45, 13244 (1992); Becke, A. D. J.Chem. Phys., 88, 2547 (1988)) which was one of DFT functions was used.The basis set chosen was the double numerical plus d-functions (DNP) inorder to confirm C, O, and H atoms.

Dmol3 (Delley B J. Chem. Phys. 92, 508, 1990; Delley B J. Chem. Phys.94, 7245, 1991; Delley B J. Chem. Phys. 113, 7756, 2000), a commercialDFT program, was used as the program of the present invention.

In order to obtain the reaction energy and the transition state, thestructures of the reactant and the product were optimized without anyconstraint.

From the energy data of the optimized reactant and product, the reactionenergy was obtained. The structure of the transition state was obtainedby means of an LST method (Complete Linear Synchronous Transit) usingthe structure estimated from the structures of the reactant and theproduct.

The calculation showed that the energy of the endo isomer was morestable by about 1.2 kcal/mol in the transition state and, in the case ofthe reaction product such as the 5-norbornene-2-methyl acetate molecule,the energy of the exo isomer was more stable by about 2.1 kcal/mol.

<Production of an Acetate Norbornene Monomer Composition>

Example 1

Dicyclopentadiene (DCPD, Maruzen, purity 99%, 66.1 g, and 0.5 mol),allyl acetate (AA, Showa Denko, 125.15 g, and 1.25 mol), andhydroquinone (HQ) acting as the polymerization inhibitor were added inan amount of 0.1 parts by weight based on 100 parts by weight of thetotal weight of DCPD and AA, and 1 mol of tetrahydrofuran (THF) actingas the solvent was also added to a 300 mL high pressure reactor. Thereactants were agitated at normal pressure for 10 min so that thepolymerization inhibitor was completely dissolved to desirably mix thereactants with each other, heated to 290° C., and agitated again at 300rpm to perform the reaction for 3 hours.

After the reaction was finished, the temperature was reduced to normaltemperature and the yellow or brown resulting solution was distilled toproduce a 5-norbornene-2-methyl acetate monomer composition.

The reaction was performed in a nitrogen (N2) atmosphere (vacuumdistillation temperature: 50 to 70° C. (Bath) and 34 to 40° C. (Head)).

Examples 2 to 9 and Comparative Examples 1 to 3

The reaction was performed by using the same procedure as Example 1 toproduce a 5-norbornene-2-methyl acetate monomer composition, except thatthe condition was set to be the same as that of Table 1.

The yield and the exo/endo ratio of the 5-norbornene-2-methyl acetatemonomer composition that were produced in Examples 1 to 9 andComparative examples 1 to 3 were measured by using the followingmethods, and the results are described in Table 1.

The yield of the product that was produced during the Diels-Alderreaction was obtained by using the weight of the product that waspurified at reduced pressure, and the purity and the exo/endo ratio ofthe product were obtained by using gas chromatography equipment that wasprovided with a flame ionization detector (FID) and an AT1000 column.

FIG. 3 is an NMR spectrum of the 5-norbornene-2-methyl acetate monomercomposition produced in Example 9.

TABLE 1 Time DCPD AA Reaction Exo/Endo Temp (° C.) (min) (mol) (mol)Solvent quotient molar ratio Example 1 290 180 0.5 1.25 THF 189668 50/50(1 mol) Example 2 310 20 0.5 1.25 THF 125029 51/49 (1 mol) Example 1 3305 0.5 1.25 THF 76118 55/45 (1 mol) Example 4 270 180 3 7.5 THF 16440950/50 (1 mol) Example 5 290 60 3 7.5 THF 149542 50/50 (1 mol) Example 6290 60 3 1.5 THF 149542 52/48 (1 mol) Example 7 270 240 0.5 1.25 CyHex173517 50/50 (1.25) Example 8 270 180 0.5 1.25 Tol 164409 52/48 (1.25)Example 9 270 300 0.5 1.25 Tol 180582 54/46 (1.25) Comparative 270 1800.5 1.25 — 164409 47/53 Example 1 Comparative 210 180 0.5 1.25 — 9945820.7/79.3 Example 2 Comparative 220 180 0.5 1.25 — 119303 33.2/67.8Example 3 In Table 1, THF is tetrahydrofuran, CyHex is cyclohexane, andTol is toluene.

From the data of Examples 1 to 3 in Table 1, it could be seen that thereaction toward the exo isomer was thermodynamically favored as thetemperature was raised; accordingly, the ratio of the thermodynamicallystable exo isomer was increased.

In addition, from the data of Examples 8 and 9, it could be seen thatthe content of exo isomer was increased as the reaction time wasincreased under the same condition.

Furthermore, from the results of Example 8 and Comparative example 1, itcould be seen that the solvent functioned to stabilize the exo isomer inthe transition state to achieve the thermodynamically advantageousreaction of the exo isomer.

<Production of a Norbornene Polymer>

Example 10 Polymerization of 5-norbornene-2-acetate where exo/endo=100/0

5-norbornene-2-acetate (NB—O—C(O)—CH₃) where exo/endo=100/0 (2.0 g, 13.2mmol, and NB denotes norbornene) and 6 ml of toluene were put into a 250mL Schlenk flask. 1 mL of dichloromethane was added to palladium acetate(Pd(OAc)₂) (OAc=acetate, 1.8 mg, and 2.64 μmol) andtricyclohexylphosphonium(tetrakis pentafluorophenyl) borate([(Cy)₃PH][B(C₆F₅)₄]) (5.1 mg and 5.28 μmol) to perform dissolution andthe resulting solution was added to the monomer solution.

The reaction temperature was increased to 90° C. and agitation wasperformed for 20 hours. After the reaction for 20 hours, 20 ml oftetrahydrofuran (THF) was added to dilute the polymer solution havingthe high viscosity, and the diluted polymer solution was added to anexcessive amount of ethanol to obtain a white copolymer precipitate.

The precipitate was filtered by using a glass funnel and the recoveredcopolymer was dried in a vacuum oven at 70° C. for 24 hours to obtain1.82 g of 5-norbornene-2-acetate polymer (91 wt % on the basis of thetotal amount of the added monomers).

The polymer was dissolved in trichlorobenzene to measure the molecularweight. The weight average molecular weight (Mw) was 104,000, and Mw/Mnwas 2.3.

Example 11 Polymerization of 5-norbornene-2-methyl acetate whereexo/endo 54/46

5-norbornene-2-methyl acetate (NB—CH₂—O—C(O)—CH₃) where exo/endo=54/46(20.775 g, 0.125 mol, and NB denotes norbornene) and toluene (62.3 g)were put into a 250 mL Schlenk flask.

1 mL of dichloromethane was added to palladium acetate (Pd(OAc)₂)(OAc=acetate, 1.9 mg, and 8 mol) and tricyclohexylphosphonium(tetrakispentafluorophenyl) borate ([(Cy)₃PH][B(C₆F₅)₄]) (16 mg and 17 μmol) toperform dissolution and the resulting solution was added to the monomersolution. The reaction temperature was increased to 90° C. and agitationwas performed for 18 hours. After the reaction for 18 hours, 62.3 g oftoluene was added to dilute the polymer solution having the highviscosity, and the diluted polymer solution was added to an excessiveamount of ethanol to obtain a white copolymer precipitate.

The precipitate was filtered by using a glass funnel and the recoveredcopolymer was dried in a vacuum oven at 70° C. for 24 hours to obtain20.35 g of 5-norbornene-2-methyl acetate polymer (98 wt % on the basisof the total amount of the added monomers).

The polymer was dissolved in tetrahydrofuran (THF) to measure themolecular weight. The weight average molecular weight (Mw) of thepolymer was 383,523, and Mw/Mn was 2.28.

Example 12 Polymerization of 5-norbornene-2-methyl acetate whereexo/endo=70/30

5-norbornene-2-methyl acetate (NB—CH₂—O—C(O)—CH₃) where exo/endo=70/30(2.06 g, 12.4 mmol, and NB denotes norbornene) and 6 mL of toluene wereput into a 250 mL Schlenk flask.

Palladium acetate (Pd(OAc)₂) (OAc=acetate, 1.7 mg, and 2.48 μmol) andtricyclohexylphosphonium(tetrakis pentafluorophenyl) borate([(Cy)₃PH][B(C₆F₅)₄]) (4.8 mg and 4.96 μmol) were used and thepolymerization was performed by using the same procedure as Example 39to recover the polymer. 1.88 g of 5-norbornene-2-methyl acetate polymer(91 wt % on the basis of the total amount of the added monomers) wasobtained by using the polymerization.

The weight average molecular weight (Mw) of the polymer was 639,000, andMw/Mn was 3.79.

Example 13 Copolymerization of 5-norbornene-2-methyl acetate whereexo/endo=90/10

5-norbornene-2-methyl acetate (NB—CH₂—O—C(O)—CH₃) where exo/endo=90/10(2.06 g, 12.4 mmol, and NB denotes norbornene) and 6 mL of toluene wereput into a 250 mL Schlenk flask. Palladium acetate (Pd(OAc)₂)(OAc=acetate, 1.7 mg, and 2.48 μmol) andtricyclohexylphosphonium(tetrakis pentafluorophenyl) borate([(Cy)₃PH][B(C₆F₅)₄]) (4.8 mg and 4.96 μmol) were used and thepolymerization was performed by using the same procedure as Example 39to recover the polymer. 2.04 g of 5-norbornene-2-methyl acetate polymer(>99 wt % on the basis of the total amount of the added monomers) wasobtained by using the polymerization.

The weight average molecular weight (Mw) of the polymer was 764,000, andMw/Mn was 4.58.

Example 14 Copolymerization of 5-norbornene-2-methyl acetate whereexo/endo=70/30 and 5-norbornene-2-acetate where exo/endo=100/0

5-norbornene-2-methyl acetate (NB—CH₂—O—C(O)—CH₃) where exo/endo=70/30(1.76 g and 10.6 mmol), 5-norbornene-2-acetate (NB—O—C(O)—CH₃) whereexo/endo=100/0 (0.40 g and 2.6 mmol), and 10 mL of toluene were put intoa 250 mL Schlenk flask.

1 mL of dichloromethane was added to palladium acetate (Pd(OAc)₂)(OAc=acetate, 1.8 mg, and 2.6 μmol) andtricyclohexylphosphonium(tetrakis pentafluorophenyl) borate([(Cy)₃PH][B(C₆F₅)₄]) (5.1 mg and 5.3 μmol) to perform dissolution andthe resulting solution was added to the monomer solution. The reactiontemperature was increased to 90° C. and agitation was performed for 3hours. After the reaction for 3 hours, the polymer was recovered byusing the same procedure as Example 39. Thereby, 1.75 g of5-norbornene-2-methyl acetate/5-norbornene-2-acetate copolymer wasobtained (81 wt % on the basis of the total amount of the addedmonomers).

The weight average molecular weight (Mw) of the polymer was 342,900, andMw/Mn was 2.89.

Example 15 Copolymerization of 5-norbornene-2-methyl acetate whereexo/endo 54/46 and butylnorbornene

5-norbornene-2-methyl acetate where exo/endo=54/46 (NB—CH₂—O—C(O)—CH₃)(14.54 g and 0.0875 mol), butylnorbornene (5.59 g and 0.0375 mol) andtoluene (40.26 g) were put into a 250 mL Schlenk flask.

1 mL of dichloromethane was added to palladium acetate (Pd(OAc)₂)(OAc=acetate, 1.9 mg, and 8 μmol) and tricyclohexylphosphonium(tetrakispentafluorophenyl) borate ([(Cy)₃PH][B(C₆F₅)₄]) (16 mg and 17 μmol) toperform dissolution and the resulting solution was added to the monomersolution. The reaction temperature was increased to 90° C. and agitationwas performed for 18 hours.

After the reaction for 18 hours, 67.1 g of toluene was added to dilutethe polymer solution having the high viscosity, and the diluted polymersolution was added to an excessive amount of ethanol to obtain a whitecopolymer precipitate. The precipitate was filtered by using a glassfunnel and the recovered copolymer was dried in a vacuum oven at 70° C.for 24 hours to obtain 19.12 g of 5-norbornene-2-methylacetate/butylnorbornene copolymer (95 wt % on the basis of the totalamount of the added monomers).

The weight average molecular weight (Mw) of the polymer was 303,550, andMw/Mn was 2.16.

Example 16 Copolymerization of 5-norbornene-2-methyl acetate whereexo/endo 70/30 and hexylnorbornene

5-norbornene-2-methyl acetate where exo/endo=70/30 (NB—CH₂—O—C(O)—CH₃)(1.10 g and 6.60 mmol), hexylnorbornene (1.17 g and 6.60 mmol), and 6 mLof toluene were put into a 250 mL Schlenk flask.

Palladium acetate (Pd(OAc)₂) (OAc=acetate, 1.8 mg, and 2.6 μmol) andtricyclohexylphosphonium(tetrakis pentafluorophenyl) borate([(Cy)₃PH][B(C₆F₅)₄]) (5.1 mg and 5.3 μmol) were used and thepolymerization was performed by using the same procedure as Example 39to recover the polymer. 2.17 g of 5-norbornene-2-methylacetate/hexylnorbornene copolymer (96 wt % on the basis of the totalamount of the added monomers) was obtained by using the polymerization.

The weight average molecular weight (Mw) of the polymer was 555,500, andMw/Mn was 3.76.

Example 17 Copolymerization of 5-norbornene-2-methyl acetate whereinexo/endo 54/46 and 5-norbornene-2-carboxylic acid methyl ester

5-norbornene-2-methyl acetate wherein exo/endo=54/46 (14.54 g and 0.0875mol), 5-norbornene-2-carboxylic acid methyl ester (5.71 g and 0.0375mol), and toluene (30.37 g) were put into a 250 mL Schlenk flask.

1 mL of dichloromethane was added to palladium acetate (Pd(OAc)₂)(OAc=acetate, 1.9 mg, and 8 μmol) and tricyclohexylphosphonium(tetrakispentafluorophenyl) borate ([(Cy)₃PH][B(C₆F₅)₄]) (16 mg and 17 μmol) toperform dissolution and the resulting solution was added to the monomersolution.

The reaction temperature was increased to 90° C. and agitation wasperformed for 18 hours. After the reaction for 18 hours, 50.61 g oftoluene was added to dilute the polymer solution having the highviscosity, and the diluted polymer solution was added to an excessiveamount of ethanol to obtain a white copolymer precipitate.

The precipitate was filtered by using a glass funnel and the recoveredcopolymer was dried in a vacuum oven at 70° C. for 24 hours to obtain18.32 g of copolymer of 5-norbornene-2-methyl acetate and5-norbornene-2-carboxylic acid methyl ester (90.5 wt % on the basis ofthe total amount of the added monomers).

The weight average molecular weight (Mw) of the polymer was 211,891, andMw/Mn was 2.67.

Example 18 Terpolymerization of 5-norbornene-2-methyl acetate whereexo/endo=70/30,5-norbornene-2-acetate where exo/endo=100/0, andhexylnorbornene

5-norbornene-2-methyl acetate where exo/endo=70/30 (NB—CH₂—O—C(O)—CH₃)(1.76 g and 10.6 mmol), 5-norbornene-2-acetate where exo/endo=100/0(NB—O—C(O)—CH₃) (0.20 g and 1.30 mmol), hexylnorbornene (0.23 g and 1.30mmol), and 10 ml of toluene were put into a 250 mL Schlenk flask. 1 mLof dichloromethane was added to palladium acetate (Pd(OAc)₂)(OAc=acetate, 1.8 mg, and 2.6 μmol) andtricyclohexylphosphonium(tetrakis pentafluorophenyl) borate([(Cy)₃PH][B(C₆F₅)₄]) (5.1 mg and 5.3 μmol) to perform dissolution andthe resulting solution was added to the monomer solution.

The reaction temperature was increased to 90° C. and agitation wasperformed for 3 hours. After the reaction for 3 hours, the polymer wasrecovered by using the same procedure as Example 39. Thereby, 1.89 g of5-norbornene-2-methyl acetate/5-norbornene-2-acetate/hexylnorbornenecopolymer was obtained (86 wt % on the basis of the total amount of theadded monomers).

The weight average molecular weight (Mw) of the polymer was 419,900, andMw/Mn was 2.60.

Example 19 Terpolymerization of 5-norbornene-2-methyl acetate whereexo/endo 54/46, butylnorbornene, and hexylnorbornene

5-norbornene-2-methyl acetate where exo/endo 54/46 (NB—CH₂—O—C(O)—CH₃)(1.10 g and 6.60 mmol), butylnorbornene (0.50 g and 3.30 mol),hexylnorbornene (0.58 g and 3.30 mol), and 6 ml of toluene were put intoa 250 mL Schlenk flask.

Palladium acetate (Pd(OAc)₂) (OAc=acetate, 1.8 mg, and 2.6 μmol) andAricyclohexylphosphonium(tetrakis pentafluorophenyl) borate([(Cy)₃PH][B(C₆FS)₄]) (5.1 mg and 5.3 μmol) were used and thepolymerization was performed by using the same procedure as Example 39to recover the polymer. 2.05 g of 5-norbornene-2-methylacetate/butylnorbornene/hexylnorbornene copolymer (94 wt % on the basisof the total amount of the added monomers) was obtained by using thepolymerization.

The weight average molecular weight (Mw) of the polymer was 510,200, andMw/Mn was 3.63.

Examples 20 to 29 Production of an Optical Film

The norbornene polymers that were produced in Examples 10 to 19 weremixed so that the compositions of Table 2 were obtained to producecoating solutions, and the coating solutions were cast on a glasssubstrate by using a knife coater or a barcoater, dried at normaltemperature for 1 hour, and additionally dried in a nitrogen atmosphereat 100° C. for 18 hours.

After the drying, the dried substrate was stored at −10° C. for 10 sec,and the film was peeled off from the glass substrate by using a knife toobtain a transparent film having a uniform thickness where a thicknessdeviation is less than 2%. The thickness and light transmission at 400to 800 nm of the film are described in the following Table 2.

(Measurement of Optical Anisotropic Properties)

In respects to the transparent films, the refractive index (n) wasmeasured by using an ABBE refractometer, the in-plane retardation value(R_(e)) was measured by using an automatic birefringence analyzer(KOBRA-21 ADH manufactured by Oji scientific instrument, Co., Ltd.), theretardation value (R_(θ)) was measured in the case where incident lightmeets the film surface at the angle of 50°, and the retardation value(R_(th)) in respects to the direction through the film thickness and thein-plane x-axis was obtained by using the following Equation 2.

$\begin{matrix}{R_{th} = \frac{R_{\theta} \times \; \cos \; \theta_{f}}{\sin^{2}\theta_{f}}} & \left( {{Equation}\mspace{20mu} 2} \right)\end{matrix}$

wherein θ is an incident angle and θ_(f) is a refraction angle of afilm.

In addition, the R_(e) and R_(th) values were divided by the thicknessof the film to obtain a difference in refractive index (n_(x)−n_(y)) anda difference in refractive index (n_(y)−n_(z)). (n_(x)−n_(y)), R_(θ),R_(th), and (n_(y)−n_(z)) of the transparent film are described in thefollowing Table 2.

TABLE 2 Composition of Physical properties of the film the film solutionLight n Polymer Sovent Thickness transmission Refractive Example (partby weight) (part by weight) (μm) (%) index (n_(x) − n_(y)) × 10³ R_(th)(nm/μm) (n_(y) − n_(z)) × 10³ 20 Polymer 100 of Toluene 560 95 92 1.530.015 4.72 4.72 Example 10 21 Polymer 100 of MC 360/ 102 91 1.52 0.0114.43 4.43 Example 11 Toluene 200 22 Polymer 100 of MC 360/ 103 91 1.520.009 4.38 4.38 Example 12 Toluene 200 23 Polymer 100 of MC 360/ 88 921.52 0.010 4.33 4.33 Example 13 Toluene 200 24 Polymer 100 of MC 360/105 91 1.52 0.014 4.52 4.52 Example 14 Toluene 200 25 Polymer 100 ofToluene 560 120 90 1.51 0.010 3.53 3.53 Example 15 26 Polymer 100 ofToluene 560 99 90 1.50 0.009 3.06 3.06 Example 16 27 Polymer 100 of MC360/ 102 91 1.53 0.007 4.66 4.66 Example 17 Toluene 200 28 Polymer 100of MC 360/ 108 91 1.51 0.011 4.10 4.10 Example 18 Toluene 200 29 Polymer100 of MC 360/ 94 90 1.50 0.005 3.11 3.11 Example 19 Toluene 200 InTable 2, MC denotes methylene chloride.

Furthermore, in the case where the triacetate cellulose film wheren_(y)>n_(z) was provided to measure R_(θ), the R_(θ) values of all thefilms were increased. This means that R_(th) of the film is caused bythe negative birefringence (n_(y)>n_(z)) in the thickness direction.

INDUSTRIAL APPLICABILITY

According to the present invention, in order to produce an acetatenorbornene monomer composition containing an exo isomer in content of 50mol % or more, variables such as a reaction temperature, a reactiontime, a molar ratio between reactants, and addition of a solvent arecontrolled. Thus, it is possible to industrially produce the acetatenorbornene monomer composition, a norbornene polymer produced using thecomposition, and an optical film including the polymer using an easyprocess.

1. A method for producing a norbornene monomer composition, comprising:the step of reacting a reaction solution that comprises cyclopentadiene,dicyclopentadiene, or a mixture of cyclopentadiene anddicyclopentadiene; a compound represented by Formula 1; and a solvent;at a reaction temperature of 230 to 330° C. for a reaction time of 5 minto 24 hours so that a content of an exo isomer is 50 mol % or more:CH₂═CH—(CH₂)_(n)—OC(O)R  <Formula 1> wherein n is an integer of 0 to 10,and R is an alkyl group having 1 to 20 carbon atoms.
 2. The method forproducing the norbornene monomer composition according to claim 1,wherein a molar ratio of the compound represented by Formula 1 tocyclopentadiene, dicyclopentadiene, or the mixture of cyclopentadieneand dicyclopentadiene in the reaction solution is in the range of 1:1 to1:10.
 3. The method for producing the norbornene monomer compositionaccording to claim 1, wherein the compound represented by Formula 1 isallyl acetate.
 4. The method for producing the norbornene monomercomposition according to claim 1, wherein the reaction solution furthercomprises at least one polymerization inhibitor selected from the groupconsisting of aniline, cyclohexane, phenol, 4-ethoxyphenol,nitrobenzene, hydroquinone, benzoquinone, copper dichloride, and2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl, and Irganox.
 5. The methodfor producing the norbornene monomer composition according to claim 4,wherein the polymerization inhibitor is contained in an amount of 0.01to 100 parts by weight based on 100 parts by weight of cyclopentadiene,dicyclopentadiene, or the mixture of cyclopentadiene anddicyclopentadiene, and the compound represented by Formula
 1. 6. Themethod for producing the norbornene monomer composition according toclaim 1, wherein the solvent contains at least one selected from thegroup consisting of cyclohexane, toluene, acetone, methyl ethyl ketone(MEK), ethyl acetate, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF),and dimethyl formamide (DMF).
 7. The method for producing the norbornenemonomer composition according to claim 1, wherein the method isperformed so that a reaction quotient represented by Equation 1 is inthe range of 25,200 to 350,000:Reaction quotient=reaction temperature (° C.)₂×log(reaction time(min)).  <Equation 1>
 8. A norbornene polymer comprising: a repeatingunit that is represented by Formula 2 and contains an exo isomer in acontent of 50 mol % or more:

wherein m is an integer of 0 to 4, n is an integer of 0 to 10, and R isan alkyl group having 1 to 20 carbon atoms.
 9. The norbornene polymeraccording to claim 8, wherein n is 0 and the content of the exo isomerin the repeating unit is 50 to 100 mol %.
 10. The norbornene polymeraccording to claim 8, wherein n is an integer of 1 to 10 and the contentof the exo isomer in the repeating unit is 50 to 90 mol %.
 11. Thenorbornene polymer according to claim 8, wherein the degree ofpolymerization is in the range of 10 to 20,000.
 12. The norbornenepolymer according to claim 11, wherein the degree of polymerization isin the range of 10 to 10,000.
 13. The norbornene polymer according toclaim 8, wherein the norbornene polymer is a homopolymer that containsone repeating unit selected from compounds represented by Formula
 2. 14.The norbornene polymer according to claim 8, wherein the norbornenepolymer is a copolymer that contains at least two repeating unitsselected from compounds represented by Formula
 2. 15. The norbornenepolymer according to claim 8, wherein the norbornene polymer is acopolymer and further comprising a polar norbornene repeating unit ofFormula 3:

wherein m is an integer of 0 to 4, at least one of R_(1a), R_(2a),R_(3a), and R_(4a) is a polar functional group containing at least oneatom selected from the group consisting of oxygen, nitrogen, phosphorus,sulfur, silicon, and boron, and R_(1a), R_(2a), R_(3a), and R_(4a) thatare not the polar functional group are each independently hydrogen;halogen; linear or branched alkyl, alkenyl, or vinyl having 1 to 20carbon atoms; cycloalkyl that is substituted or unsubstituted withhydrocarbon and has 5 to 12 carbon atoms; aryl that is substituted orunsubstituted with hydrocarbon and has 6 to 40 carbon atoms; aralkylthat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; alkynyl that has 3 to 20 carbon atoms; linear or branchedhaloalkyl, haloalkenyl, or halovinyl that has 1 to 20 carbon atoms;halocycloalkyl that is substituted or unsubstituted with hydrocarbon andhas 5 to 12 carbon atoms; haloaryl that is substituted or unsubstitutedwith hydrocarbon and has 6 to 40 carbon atoms; haloaralkyl that issubstituted or unsubstituted with hydrocarbon and has 7 to 15 carbonatoms; haloalkynyl that has 3 to 20 carbon atoms; an alkylidene groupthat is formed by bonding of R_(1a) and R_(2a) or R_(3a) and R_(4a) andhas 1 to 10 carbon atoms; a saturated or unsaturated cyclic group thatis formed by bonding of R_(1a) or R_(2a) to either of R_(3a) and R_(4a)and has 4 to 12 carbon atoms; or an aromatic cyclic compound that has 6to 24 carbon atoms.
 16. The norbornene polymer according to claim 15,wherein said polar functional group in Formula 3 is —C(O)OR₆,—R₅C(O)OR₆, —OR₆, —R₅OR₆, —OC(O)OR₆, —R₅OC(O)OR₆, —C(O)R₆, —R₅C(O)R₆,—OC(O)R₆, —R₅OC(O)R₆, —(R₅O)_(p)—OR₆, —(OR₅)_(p)—OR₆, —C(O)—O—C(O)R(,—R₅C(O)—O—C(O)R₆, —SR₆, —R₅SR₆, —SSR₆, —R₅SSR₆, —S(═O)R₆, —R₅S(═O)R₆,—R₅C(═S)R₆, —R₅C(═S)SR₆, —R₅SO₃R₆, —SO₃R₆, —R₅N═C═S, —N═C═S, —NCO,R₅—NCO, —CN, —R₅CN, —NNC(═S)R₆, —R₅NNC(═S)R₆, —NO₂, —R₅NO₂,

wherein each R₅ is each independently linear or branched alkylene,haloalkylene, alkenylene, haloalkenylene, vinylene, or halovinylene thathas 1 to 20 carbon atoms; cycloalkylene or halocycloalkylene that issubstituted or unsubstituted with hydrocarbon and has 4 to 12 carbonatoms; arylene or haloarylene that is substituted or unsubstituted withhydrocarbon and has 6 to 40 carbon atoms; aralkylene or haloaralkylenethat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; or alkynylene or haloalkynylene that has 3 to 20 carbonatoms, each R₆, R₇, and R₈ are independently hydrogen; halogen; linearor branched alkyl, haloalkyl, alkenyl, haloalkenyl, vinyl, halovinyl,alkoxy, haloalkoxy, carbonyloxy, or halocarbonyloxy that has 1 to 20carbon atoms; cycloalkyl or halocycloalkyl that is substituted orunsubstituted with hydrocarbon and has 4 to 12 carbon atoms; aryl,haloaryl, aryloxy, or haloaryloxy that is substituted or unsubstitutedwith hydrocarbon and has 6 to 40 carbon atoms; aralkyl or haloaralkylthat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; or alkynyl or haloalkynyl that has 3 to 20 carbon atoms,and each p are independently is an integer of 1 to
 10. 17. Thenorbornene polymer according to claim 15, wherein a molar ratio of therepeating unit represented by Formula 2 and the repeating unitrepresented by Formula 3 is in the range of 1:700 to 700:1.
 18. Thenorbornene polymer according to claim 17, wherein a molar ratio of therepeating unit represented by Formula 2 and the repeating unitrepresented by Formula 3 is in the range of 1:100 to 100:1.
 19. Thenorbornene polymer according to claim 8, wherein the norbornene polymeris a copolymer further comprising a nonpolar norbornene repeating unitof Formula 4:

wherein m is an integer of 0 to 4, and R_(1b), R_(2b), R_(3b), andR_(4b) are each independently hydrogen; halogen; linear or branchedalkyl, alkenyl, or vinyl having 1 to 20 carbon atoms; cycloalkyl that issubstituted or unsubstituted with hydrocarbon and has 5 to 12 carbonatoms; aryl that is substituted or unsubstituted with hydrocarbon andhas 6 to 40 carbon atoms; aralkyl that is substituted or unsubstitutedwith hydrocarbon and has 7 to 15 carbon atoms; alkynyl that has 3 to 20carbon atoms; linear or branched haloalkyl, haloalkenyl, or halovinylthat has 1 to 20 carbon atoms; halocycloalkyl that is substituted orunsubstituted with hydrocarbon and has 5 to 12 carbon atoms; haloarylthat is substituted or unsubstituted with hydrocarbon and has 6 to 40carbon atoms; haloaralkyl that is substituted or unsubstituted withhydrocarbon and has 7 to 15 carbon atoms; haloalkynyl that has 3 to 20carbon atoms; an alkylidene group that is formed by bonding of R_(1b)and R_(2b) or R_(3b) and R_(4b) and has 1 to 10 carbon atoms; asaturated or unsaturated cyclic group that is formed by bonding ofR_(1b) or R_(2b) to either of R_(3b) and R_(4b) and has 4 to 12 carbonatoms; or an aromatic cyclic compound that has 6 to 24 carbon atoms. 20.The norbornene polymer according to claim 19, wherein a molar ratio ofthe repeating unit represented by Formula 2 and the repeating unitrepresented by Formula 4 is in the range of 1:700 to 700:1.
 21. Thenorbornene polymer according to claim 20, wherein a molar ratio of therepeating unit represented by Formula 2 and the repeating unitrepresented by Formula 4 is in the range of 1:100 to 100:1.
 22. Thenorbornene polymer according to claim 8, wherein the norbornene polymeris a copolymer and further comprises a polar norbornene repeating unitrepresented by Formula 3 and a nonpolar norbornene repeating unitrepresented by Formula 4:

wherein each m is independently an integer of 0 to 4, at least one ofR_(1a), R_(2a), R_(3a), and R_(4a) is a polar functional groupcontaining at least one atom selected from the group consisting ofoxygen, nitrogen, phosphorus, sulfur, silicon, and boron, and R_(1a),R_(2a), R_(3a), and R_(4a) that are not the polar functional group areeach independently hydrogen; halogen; linear or branched alkyl, alkenyl,or vinyl having 1 to 20 carbon atoms; cycloalkyl that is substituted orunsubstituted with hydrocarbon and has 5 to 12 carbon atoms; aryl thatis substituted or unsubstituted with hydrocarbon and has 6 to 40 carbonatoms; aralkyl that is substituted or unsubstituted with hydrocarbon andhas 7 to 15 carbon atoms; alkynyl that has 3 to 20 carbon atoms; linearor branched haloalkyl, haloalkenyl, or halovinyl that has 1 to 20 carbonatoms; halocycloalkyl that is substituted or unsubstituted withhydrocarbon and has 5 to 12 carbon atoms; haloaryl that is substitutedor unsubstituted with hydrocarbon and has 6 to 40 carbon atoms;haloaralkyl that is substituted or unsubstituted with hydrocarbon andhas 7 to 15 carbon atoms; haloalkynyl that has 3 to 20 carbon atoms; analkylidene group that is formed by bonding of R_(1a) and R_(2a) orR_(3a) and R_(4a) and has 1 to 10 carbon atoms; a saturated orunsaturated cyclic group that is formed by bonding of R_(1a) or R_(2a)to either of R_(3a) and R_(4a) and has 4 to 12 carbon atoms; or anaromatic cyclic compound that has 6 to 24 carbon atoms, and R_(1b),R_(2b), R_(3b), and R_(4b) are each independently hydrogen; halogen;linear or branched alkyl, alkenyl, or vinyl having 1 to 20 carbon atoms;cycloalkyl that is substituted or unsubstituted with hydrocarbon and has5 to 12 carbon atoms; aryl that is substituted or unsubstituted withhydrocarbon and has 6 to 40 carbon atoms; aralkyl that is substituted orunsubstituted with hydrocarbon and has 7 to 15 carbon atoms; alkynylthat has 3 to 20 carbon atoms; linear or branched haloalkyl,haloalkenyl, or halovinyl that has 1 to 20 carbon atoms; halocycloalkylthat is substituted or unsubstituted with hydrocarbon and has 5 to 12carbon atoms; haloaryl that is substituted or unsubstituted withhydrocarbon and has 6 to 40 carbon atoms; haloaralkyl that issubstituted or unsubstituted with hydrocarbon and has 7 to 15 carbonatoms; haloalkynyl that has 3 to 20 carbon atoms; an alkylidene groupthat is formed by bonding of R_(1b) and R_(2b) or R_(3b) and R_(4b) andhas 1 to 10 carbon atoms; a saturated or unsaturated cyclic group thatis formed by bonding of R_(1b) or R_(2b) to either of R_(3b) and R_(4b)and has 4 to 12 carbon atoms; or an aromatic cyclic compound that has 6to 24 carbon atoms.
 23. The norbornene polymer according to claim 22,wherein the molar ratio of the repeating unit of Formula 2 and the sumof the repeating units of Formulae 3 and 4 is 1:1,400 to 1,400:1, andthe molar ratio of the polar repeating unit of Formula 3 and thenonpolar repeating unit of Formula 4 is 1:700 to 700:1.
 24. Thenorbornene polymer according to claim 23, wherein the molar ratio of therepeating unit of Formula 2 and the sum of the repeating units ofFormulae 3 and 4 is 1:500 to 500:1, and the molar ratio of the polarrepeating unit of Formula 3 and the nonpolar repeating unit of Formula 4is 1:100 to 100:1.
 25. The norbornene polymer according to claim 22,wherein the polar functional group in Formula 3 is —C(O)OR₆, —R₅C(O)OR₆,—OR₆, —R₅OR₆, —OC(O)OR₆, —R₅OC(O)OR₆, —C(O)R₆, —R₅C(O)R₆, —OC(O)R₆,—R₅OC(O)R₆, —(R₅O)_(p)—OR₆, —(OR₅)_(p)—OR₆, —C(O)—O—C(O)R₆,—R₅C(O)—O—C(O)R₆, —SR₆, —R₅SR₆, —SSR₆, —R₅SSR₆, —S(═O)R₆, —R₅S(═O)R₆,—R₅C(═S)R₆, —R₅C(═S)SR₆, —R₅SO₃R₆, —SO₃R₆, —R₅N═C═S, —N═C═S, —NCO,R₅—NCO, —CN, —R₅CN, —NNC(═S)R₆, —R₅NNC(═S)R₆, —NO₂, —R₅NO₂,

wherein each R₅ is independently linear or branched alkylene,haloalkylene, alkenylene, haloalkenylene, vinylene, or halovinylene thathas 1 to 20 carbon atoms; cycloalkylene or halocycloalkylene that issubstituted or unsubstituted with hydrocarbon and has 4 to 12 carbonatoms; arylene or haloarylene that is substituted or unsubstituted withhydrocarbon and has 6 to 40 carbon atoms; aralkylene or haloaralkylenethat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; or alkynylene or haloalkynylene that has 3 to 20 carbonatoms, each R₆, R₇, and R₈ are independently hydrogen; halogen; linearor branched alkyl, haloalkyl, alkenyl, haloalkenyl, vinyl, halovinyl,alkoxy, haloalkoxy, carbonyloxy, or halocarbonyloxy that has 1 to 20carbon atoms; cycloalkyl or halocycloalkyl that is substituted orunsubstituted with hydrocarbon and has 4 to 12 carbon atoms; aryl,haloaryl, aryloxy, or haloaryloxy that is substituted or unsubstitutedwith hydrocarbon and has 6 to 40 carbon atoms; aralkyl or haloaralkylthat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; or alkynyl or haloalkynyl that has 3 to 20 carbon atoms,and each p is independently is an integer of 1 to
 10. 26. An opticalfilm comprising the norbornene polymer according to claim
 8. 27. Theoptical film according to claim 26, wherein the optical film is apolarizer protection film for LCDs or a plastic substrate which is asubstitute for a glass substrate.
 28. The optical film according toclaim 26, wherein the optical film is optically anisotropic so that aretardation value (R_(th)) represented by Equation 1 is 70 to 1000 nm:R _(th)=Δ(n _(y) −n _(z))×d  <Equation 1> wherein n_(y) is an in-planerefractive index of a fast axis that is measured at a wavelength of 550nm, n_(z) is a thickness refractive index that is measured at awavelength of 550 nm, and d is a thickness of a film.
 29. The opticalfilm according to claim 28, wherein the optical film is a negativeC-plate type optical compensation film for liquid crystal displays(LCDs) satisfying a refractive index correlation where n_(x)≈n_(y)>n_(z)(n_(x) is an in-plane refractive index of a slow axis, n_(y) is therefractive index of a fast axis, and n_(z) is a thickness refractiveindex).
 30. A method for producing a norbornene polymer that isrepresented by Formula 5, comprising: bringing a reactant that containsa norbornene monomer composition having an exo isomer in a content of 50mol % or more into contact with a catalyst of a transition metal ofGroup 10:

wherein m is an integer in the range of 0 to 4, n is an integer in therange of 0 to 10, and R is an alkyl group having 1 to 20 carbon atoms.31. The method for producing a norbornene polymer according to claim 30,wherein the monomer composition contains only one type of monomerselected from compounds represented by Formula
 5. 32. The method forproducing a norbornene polymer according to claim 30, wherein themonomer composition contains at least two types of monomers selectedfrom compounds represented by Formula
 5. 33. The method for producing anorbornene polymer according to claim 30, wherein the reactant furthercontains a polar norbornene monomer represented by Formula 6:

wherein m is an integer of 0 to 4, at least one of R_(1a), R_(2a),R_(3a), and R_(4a) is a polar functional group containing at least oneatom selected from the group consisting of oxygen, nitrogen, phosphorus,sulfur, silicon, and boron, and R_(1a), R_(2a), R_(3a), and R_(4a) thatare not the polar functional group are each independently hydrogen;halogen; linear or branched alkyl, alkenyl, or vinyl having 1 to 20carbon atoms; cycloalkyl that is substituted or unsubstituted withhydrocarbon and has 5 to 12 carbon atoms; aryl that is substituted orunsubstituted with hydrocarbon and has 6 to 40 carbon atoms; aralkylthat is substituted or unsubstituted with hydrocarbon and has 7 to 15carbon atoms; alkynyl that has 3 to 20 carbon atoms; linear or branchedhaloalkyl, haloalkenyl, or halovinyl that has 1 to 20 carbon atoms;halocycloalkyl that is substituted or unsubstituted with hydrocarbon andhas 5 to 12 carbon atoms; haloaryl that is substituted or unsubstitutedwith hydrocarbon and has 6 to 40 carbon atoms; haloaralkyl that issubstituted or unsubstituted with hydrocarbon and has 7 to 15 carbonatoms; haloalkynyl that has 3 to 20 carbon atoms; an alkylidene groupthat is formed by bonding of R_(1a) and R_(2a) or R_(3a) and R_(4a) andhas 1 to 10 carbon atoms; a saturated or unsaturated cyclic group thatis formed by bonding of R_(1a) or R_(2a) to either of R_(3a) and R_(4a)and has 4 to 12 carbon atoms; or an aromatic cyclic compound that has 6to 24 carbon atoms.
 34. The method for producing a norbornene polymeraccording to claim 30, wherein the reactant further contains a nonpolarnorbornene monomer represented by Formula 7:

wherein m is an integer of 0 to 4, and R_(1b), R_(2b), R_(3b), andR_(4b) are each independently hydrogen; halogen; linear or branchedalkyl, alkenyl, or vinyl having 1 to 20 carbon atoms; cycloalkyl that issubstituted or unsubstituted with hydrocarbon and has 5 to 12 carbonatoms; aryl that is substituted or unsubstituted with hydrocarbon andhas 6 to 40 carbon atoms; aralkyl that is substituted or unsubstitutedwith hydrocarbon and has 7 to 15 carbon atoms; alkynyl that has 3 to 20carbon atoms; linear or branched haloalkyl, haloalkenyl, or halovinylthat has 1 to 20 carbon atoms; halocycloalkyl that is substituted orunsubstituted with hydrocarbon and has 5 to 12 carbon atoms; haloarylthat is substituted or unsubstituted with hydrocarbon and has 6 to 40carbon atoms; haloaralkyl that is substituted or unsubstituted withhydrocarbon and has 7 to 15 carbon atoms; haloalkynyl that has 3 to 20carbon atoms; an alkylidene group that is formed by bonding of R_(1b)and R_(2b) or R_(3b) and R_(4b) and has 1 to 10 carbon atoms; asaturated or unsaturated cyclic group that is formed by bonding ofR_(1b) or R_(2b) to either of R_(3b) and R_(4b) and has 4 to 12 carbonatoms; or an aromatic cyclic compound that has 6 to 24 carbon atoms. 35.The method for producing a norbornene polymer according to claim 30,wherein the reactant further contains a polar norbornene monomerrepresented by Formula 6 and a nonpolar norbornene monomer representedby Formula 7:

wherein each m is independently an integer of 0 to 4, at least one ofR_(1a), R_(2a), R_(3a), and R_(4a) is a polar functional groupcontaining at least one atom selected from the group consisting ofoxygen, nitrogen, phosphorus, sulfur, silicon, and boron, and R_(1a),R_(2a), R_(3a), and R_(4a) that are not the polar functional group areeach independently hydrogen; halogen; linear or branched alkyl, alkenyl,or vinyl having 1 to 20 carbon atoms; cycloalkyl that is substituted orunsubstituted with hydrocarbon and has 5 to 12 carbon atoms; aryl thatis substituted or unsubstituted with hydrocarbon and has 6 to 40 carbonatoms; aralkyl that is substituted or unsubstituted with hydrocarbon andhas 7 to 15 carbon atoms; alkynyl that has 3 to 20 carbon atoms; linearor branched haloalkyl, haloalkenyl, or halovinyl that has 1 to 20 carbonatoms; halocycloalkyl that is substituted or unsubstituted withhydrocarbon and has 5 to 12 carbon atoms; haloaryl that is substitutedor unsubstituted with hydrocarbon and has 6 to 40 carbon atoms;haloaralkyl that is substituted or unsubstituted with hydrocarbon andhas 7 to 15 carbon atoms; haloalkynyl that has 3 to 20 carbon atoms; analkylidene group that is formed by bonding of R_(1a) and R_(2a) orR_(3a) and R_(4a) and has 1 to 10 carbon atoms; a saturated orunsaturated cyclic group that is formed by bonding of R_(1a) or R_(2a)to either of R_(3a) and R_(4a) and has 4 to 12 carbon atoms; or anaromatic cyclic compound that has 6 to 24 carbon atoms, and R_(1b),R_(2b), R_(3b), and R_(4b) are each independently hydrogen; halogen;linear or branched alkyl, alkenyl, or vinyl having 1 to 20 carbon atoms;cycloalkyl that is substituted or unsubstituted with hydrocarbon and has5 to 12 carbon atoms; aryl that is substituted or unsubstituted withhydrocarbon and has 6 to 40 carbon atoms; aralkyl that is substituted orunsubstituted with hydrocarbon and has 7 to 15 carbon atoms; alkynylthat has 3 to 20 carbon atoms; linear or branched haloalkyl,haloalkenyl, or halovinyl that has 1 to 20 carbon atoms; halocycloalkylthat is substituted or unsubstituted with hydrocarbon and has 5 to 12carbon atoms; haloaryl that is substituted or unsubstituted withhydrocarbon and has 6 to 40 carbon atoms; haloaralkyl that issubstituted or unsubstituted with hydrocarbon and has 7 to 15 carbonatoms; haloalkynyl that has 3 to 20 carbon atoms; an alkylidene groupthat is formed by bonding of R_(1b) and R_(2b) or R_(3b) and R_(4b) andhas 1 to 10 carbon atoms; a saturated or unsaturated cyclic group thatis formed by bonding of R_(1b) or R_(2b) to either of R_(3b) and R_(4b)and has 4 to 12 carbon atoms; or an aromatic cyclic compound that has 6to 24 carbon atoms.